ANTIBACTERIAL, PLASMONIC, AND TOXIC PROPERTIES OF ENGINEERED NANOPARTICLES A Thesis presented to the Faculty of the Graduate School University of Missouri In Partial Fulfillment of the Requirements fo[.]
ANTIBACTERIAL, PLASMONIC, AND TOXIC PROPERTIES OF ENGINEERED NANOPARTICLES A Thesis presented to the Faculty of the Graduate School University of Missouri In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy by Trang Ha Dieu Nguyen Drs Mengshi Lin, Azlin Mustapha Thesis Supervisors DECEMBER 2016 © Copyright by Trang Ha Dieu Nguyen 2016 All rights reserved The undersigned, appointed by the dean of the Graduate School, have examined the thesis entitled ANTIBACTERIAL, PLASMONIC AND TOXIC PROPERTIES OF ENGINEERED NANOPARTICLES Presented by Trang Ha Dieu Nguyen, a candidate for the degree of Doctor of Philosophy, and hereby certify that, in their opinion, it is worthy of acceptance Mengshi Lin, Ph.D., Food Science Program Azlin Mustapha, Ph.D., Food Science Program Bongkosh Vardhanabhuti, Ph.D., Food Science Program Chong He, Ph.D., Department of Statistics ACKNOWLEDGEMENTS In the heat of moment, when many ideas for the acknowledgment part of my dissertation come along, I was so excited This dissertation took me four and a half years and it has given me much of challenges and joyfulness This work would not have been possible without the guidance and supports of all the following individuals First and foremost, I would like to thank my two wonderful advisors, Drs Mengshi Lin and Azlin Mustapha Dr Lin is a facilitator and a mentor who abundantly helped and offered me invaluable assistance, supports and encouragements during my time in Mizzou I believe he spent hundreds of hours editing my manuscripts, even in the weekends Dr Mustapha inspired me by her enthusiasm, energy, and excellent knowledge I cannot fulfill my dissertation without her advice and guidance when I had problems with my experiments She is the person who has proven that a female scientist can balance well between her family and career! I would like to show my gratitude to my committee members, Dr Vardhanabhuti and Dr He through the journey I appreciate their valuable suggestions and comments, especially Dr V for her co-authorship in one of my manuscripts I also would like to express my thanks to Dr Koc, Dr Clarke, Dr Gruen, Dr Elmore, Dr Alexander for letting me help them in teaching assistance I have learned from them teaching methods, curricula and appropriate manner when interacting with students ii I thank my past and present lab members and from different labs for being wonderful colleagues to work with Special thanks are given to Zhang Zhong for his co-authorship and assistance I acknowledge the Vietnam International Education Development under the Ministry of Education and Training for financial support in the first two years of my study Finally, I owe my deepest gratitude to my family in Vietnam and my husband’s family in the US for endless love, support, and encouragement, without which I could not finish my work My husband and my sons Yanni and Raphael are the greatest gifts that God brought to me Thank you all for being with me, loving me unconditionally, being my support and inspiring me every single day of my life iii TABLE OF CONTENTS ACKNOWLEDGEMENTS ii LIST OF TABLES vii LIST OF FIGURES viii ABSTRACT xi CHAPTER Introduction 1.1 Background 1.2 Objectives CHAPTER Literature review 2.1 Nanomaterials and current uses in foods and consumer products 2.2 Surface enhanced Raman spectroscopy (SERS) and its enhancement mechanisms 13 2.3 Applications of SERS for Food Adulterant Detection 17 2.4 SERS substrates 18 2.5 Antibacterial properties of inorganic ENPs 20 2.6 Mechanisms of antimicrobial properties of inorganic ENPs 26 2.7 Physical and chemical properties of inorganic ENPS affect their antimicrobial activities 29 2.8 Cytotoxicity of inorganic NPs to human cells 32 2.9 Mechanisms of cytoxocity of ENPS 35 2.10 Physical and chemical properties of NMs associated with nanotoxicity 36 2.11 Toxicity Assessment of NPs 39 2.11.1 Cell uptake 40 2.11.2 Cell viability 41 2.11.3 Cell functions 41 CHAPTER 48 Use of Graphene and Gold Nanorods as Substrates for Detection of Pesticides by Surface Enhanced Raman Spectroscopy 48 iv 3.1 Introduction 50 3.2 Materials and Methods 52 3.2.1 Preparation of chemicals 52 3.2.2 Gold film silicon substrate 53 3.2.3 Synthesis of gold nanorods 53 3.2.4 Fabrication of SERS substrates 54 3.2.5 SERS measurements 55 3.2.6 Data analysis 55 3.3 Results and Discussions 57 CHAPTER 69 Use of Aminothiophenol as an Indicator for the Analysis of Silver Nanoparticles in Consumer Products by Surface-Enhanced Raman Spectroscopy (SERS) 69 4.1 Introduction 71 4.2 Materials and Methods 74 4.2.1 Materials 74 4.2.2 Characterization of Ag NPs in the products 75 4.2.3 Determine Ag NPs in tested products 75 4.2.4 Conjugation of PATP onto Ag NPs 75 4.2.5 Detection of Ag NPs Using SERS and PATP-Ag NPs conjugation 76 4.2.6 Data Analysis 76 4.3 Results and Discussion 77 CHAPTER 86 Toxicity of Graphene Oxide on Intestinal Bacteria, and Caco-2 Cells 86 5.1 Introduction 87 5.2 Materials and Methods 89 5.2.1 Characterization of GO 89 5.2.2 Preparation of Bacterial strains 90 5.2.3 Effect of GO on the growth of E coli, L acidophilus, and B animalis 90 5.2.4 Mammalian cell study 91 5.2.5 MTT reduction assay 92 5.2.6 WST-8 proliferation assay 93 5.2.7 Scanning electron microscopy (SEM) analysis 93 v 5.2.8 Transmission electron microscopy (TEM) analysis 94 5.2.9 Statistical analysis 94 5.3 Results and Discussion 95 CHAPTER 108 Antibacterial Properties of Selenium Nanoparticles and Their Toxicity on Caco-2 Cells 108 6.1 Introduction 109 6.2 Materials and Methods 110 6.2.1 Chemicals, bacterial strains mammalian cells 110 6.2.2 Characterization of Se NPs 111 6.2.3 Preparation of bacterial strains 112 6.2.4 Synthesis of Se NPs 112 6.2.5 Effect of Se NPs on the growth of bacterial strains 113 6.2.6 Mammalian cell study 113 6.2.7 MTT reduction assay 114 6.2.8 WST-8 proliferation assay 114 6.2.9 Scanning electron microscopy (SEM) 115 6.2.10 Transmission electron microscopy (TEM) 115 6.2.11 Statistical analysis 116 6.3 Results and Discussion 116 6.3.1 Characterization of Se NPs 116 6.3.2 Antibacterial effects of Se NPs on pathogenic bacteria 118 6.3.3 Cytotoxic effect of Se NPs on Caco-2 cells 124 CHAPTER 128 Conclusions and Future Plans 128 Appendix 131 References 132 VITA 169 vi LIST OF TABLES Table Page Table Food and Food-related products that claim to contain nanoparticles Table Antibacterial effect of inorganic ENPs against different microorganisms 20 Table In vitro cytotoxicity effects of graphene materials and Se NPs 33 Table Band assignment of major peak in SER spectra form three pesticides* 63 Table Limit of detection of using G-Au-AuNRS substrate for detection of azinphosmethyl, carbaryl, and phosmet 68 Table Total concentration of silver and Ag NPs, average size, and the intensity of SERS spectra acquired from five commercial products 84 Table GO characteristics, values presented means ± SD from triplicate measurements 97 Table The zeta-potential values of selenium nanoparticles 118 Table Zeta potential values of bacteria strains 124 vii LIST OF FIGURES Figure Page Figure 2-1 Schematic of a surface-enhanced light scattering process (Schatz and others 2006; Alonso-González and others 2012) 14 Figure 3-1 Structure of substrates: (a) graphene-Au-AuNR (G-Au-AuNR); (b) grapheneAuNR (G-AuN); (c) Au-AuNR 54 Figure 4-1 SERS spectra of PATP, PATP mixed with AgNO3, PATP with 30 nm Ag NP3 78 Figure 4-2 Comparisons of enhancement effects from Ag NPs 79 Figure 4-3 Concentration-dependent SERS spectra (part of full scale) of Ag NPs with PATP (10 mg/mL) as an indicator (A); the linear relation between Raman intensity and Ag NPs concentration (B) 80 Figure 4-4 SERS spectra four five Ag NPs-containing dietary and antimicrobial products Negative controls were prepared using the solvent of PATP (methanol) 82 Figure 4-5 Characterization of Ag NPs in the dietary supplements and antimicrobial products (A) Dietary supplement; (B) nasal spray; (C) dietary supplement; (D) dietary supplement; (E) dietary supplement 83 Figure 5-1 UV–vis absorption spectrum of GO aqueous dispersion (A) FTIR spectrum of dried graphite oxide sample (B) 96 Figure 5-2 TEM images of GO aqueous dispersion 96 viii